Method and device for channel estimation in wireless communication system supporting MIMO
Disclosed is a method for estimating a channel of a terminal by a base station in a wireless communication system supporting multiple antennas, the method comprising the steps of: estimating a moving speed of the terminal on the basis of a first channel value acquired at a current time point and a second channel value acquired at a previous time point; determining, on the basis of the estimated moving speed, a complexity degree corresponding to the number of channel values for multiple time points including the current time point; and estimating a channel of the terminal at a next time point on the basis of the determined complexity degree.
1. A method for estimating a channel of a user equipment (UE) by a base station in a wireless communication system supporting multiple antennas, the channel estimation method comprising:
estimating a movement speed of the UE, based on a first channel value obtained at a current time point and a second channel value obtained at a previous time point;
determining, based on the estimated movement speed, a complexity order corresponding to the number of channel values for multiple time points comprising the current time point; and
estimating a channel of the UE at a next time point, based on the determined complexity order.
2. The channel estimation method of claim 1 , wherein the complexity order is proportional to an amount of change in a channel according to movement of the UE.
3. The channel estimation method of claim 1 ,
wherein the complexity order corresponds to the number of multiple signals received from the UE through multiple channels at the multiple time points, and
wherein the complexity order is determined by a ratio value of the movement speed.
4. The channel estimation method of claim 1 ,
wherein the estimating of the channel at the next time point further comprises preprocessing the multiple received signals to obtain multiple channel vectors, and
wherein the preprocessing uses a linear minimum mean square error estimation (LMMSE) method.
5. The channel estimation method of claim 4 ,
wherein the estimating of the channel at the next time point further comprises estimating the channel at the next time point through a multi-layer perceptron (MLP) into which the multiple channel vectors obtained through the preprocessing are input, and
wherein the MLP has a structure comprising at least one hidden layer for updating multiple weights used to estimate the channel at the next time point.
6. The channel estimation method of claim 5 , further comprising:
training through which multiple weights are updated in the MLP,
wherein the multiple weights are updated such that a channel value at the next time point, at which a loss of a cost function is minimized in the training, is estimated.
7. The channel estimation method of claim 1 , wherein the estimating of the channel at the next time point further comprises estimating a channel value at the next time point by using a channel value at the current time point and a channel value at the previous time point through a Kalman filter.
8. A base station for estimating a channel of a user equipment (UE) in a wireless communication system supporting multiple antennas, the base station comprising:
a transceiver; and
a processor,
wherein the processor is configured to:
estimate a movement speed of the UE, based on a first channel value obtained at a current time point and a second channel value obtained at a previous time point,
determine, based on the estimated movement speed, a complexity order corresponding to the number of channel values for multiple time points comprising the current time point, and
estimate a channel of the UE at a next time point, based on the determined complexity order.
9. The base station of claim 8 , wherein the complexity order is proportional to an amount of change in a channel according to movement of the UE.
10. The base station of claim 8 ,
wherein the complexity order corresponds to the number of multiple signals received from the UE through multiple channels at the multiple time points, and
wherein the processor is configured to determine the complexity order by a ratio value of the movement speed.
11. The base station of claim 8 ,
wherein the processor is configured to preprocess the multiple received signals to obtain multiple channel vectors, and
wherein the preprocessing uses a linear minimum mean square error estimation (LMMSE) method.
12. The base station of claim 11 ,
wherein the processor is configured to estimate the channel at the next time point through a multi-layer perceptron (MLP) into which the multiple channel vectors obtained through the preprocessing are input, and
wherein the MLP has a structure comprising at least one hidden layer for updating multiple weights used to estimate the channel at the next time point.
13. The base station of claim 12 , wherein the processor is configured to:
update multiple weights in the MLP through training; and
update the multiple weights such that a channel value at the next time point, at which a loss of a cost function is minimized in the training, is estimated.
14. The base station of claim 8 , wherein the processor is configured to estimate a channel value at the next time point by using a channel value at the current time point and a channel value at the previous time point through a Kalman filter.
15. The base station of claim 8 , wherein the processor is configured to:
calculate a minimum prediction mean square error (MSE) matrix such that a channel value at the next time point is estimated or corrected using a channel value at the current time point;
determine a Kalman gain matrix by using the estimated MSE matrix; and
estimate the channel at the next time point by using the Kalman gain matrix.